Add two RS232, and two RS422/485 serial ports to your PC through a PCI-Express expansion slotThe PEX4S232485 4 Port PCI Express PCIe Serial Combo Card - 2 x RS232 2 x RS422 / RS485 lets you add two RS232, and two RS422/485 serial ports to your PC through a PCI-Express expansion slot.This PCI express serial card is a single card solution that is compatible with nearly any serial communication protocol, supporting RS-232, RS-422, RS-485 2-wire or RS-485 4-wire operating modes. A flexible solution for adding serial ports to full-sized, or small form factor systems, the 4-port serial card includes both low and full profile brackets while the included breakout cable helps to avoid cluttered connections.Backed by a StarTech.com lifetime warranty and free lifetime technical support.The StarTech.com Advantage- This single PCI Express combo card is compatible with any serial device protocol (RS232, RS422, and RS485), allowing for communication with multiple devices over mixed protocols- Includes both low profile/half-height and full profile brackets to ensure fitment into a broad range of system form factors- The included breakout cable saves expense as an all-in-one solution, and allows the addition of multiple serial ports through a single PCI Express slot